DL380 G3-Array B has 3-146gb drives / recognizes 273GB)

[Christina Passama]

The DL380 G3 has 5 drives: 2-72gb and 4-146g
Array A = 2-72GB hard drives
Array B = 3-146GB hard drives
Both share a global online spare 146gb
When buidling the logical drive, I added all 3-146GB hard drives; however, the max size = 280019 MB which =273GB. It should be showing approximately 438Gb.

The Array Configruation Utility is v. 7.85.18.0 and I'm not sure if this is a 5300, 6400

Does this need to be upgraded? Also, I vaguely remember seeing a utility/tool/support pack that allowed you to run an executable on the server which showed you the current version of all firmware and then recommended various upgrades which could be executed by selecting them. I was not sure what to select in the Dowload Drivers for the DL380 G3. Any help you can give me is GREATLY appreciated.

:-)
Thanks,
Christina

[Christina Passama]

Additional information
Array A = Raid 1+0
Array B = Raid 5
Both share the global online spare
OS = Windows Standard Server 2003 x-86

[Blazhev_1 · Accepted solution]

Hi Christina,

when you make raid 5, one drive is used to store parity information, so that if a drive fails , the information can be reconstructed from the other drives and the parity information.

The size you can use with RAID 5 is N-1, where N is the number of drives in the logical drive...
Same from your RAID 1 -> it is N/2(half of the space is a mirror/copy of the info), so your first logical drive is 72GB only, not 2x72GB = 146GB.

Spare in this configuration with such logical drives, doesn't seem very suitale if the info is not veryyyy important and you fear a 2 HDD failure at one day.

2HDDs in RAID 1 - > 1 can fail and info will remain.

3HDDs in RAID 5 - > 1 can fail and info will remain.

If you delete the spare and make a RAID 5 from the 4 x 146 drives , then space will be around 400GB(N-1 x ~137 ). 137 instead of 146, because the drive space is calculated differently.

Pac

[KarloChacon]

hi Christina

something to read
http://www.acnc.com/04_01_00.html

something to have handy
http://www.ibeast.com/content/tools/RaidCalc/RaidCalc.asp

regards

[Christina Passama]

Hi Pac and Karlo:

I am very grateful for your explanations and links. They really helped me understand why the Raid 5 was not showing the 438gb of space.

Thank you very much for your expertise and willingness to share the wealth of information.

:-)
Sincerely,
Christina